|South, Paul - FDA/COLLEGE PARK, MD|
Submitted to: Biological Trace Element Research
Publication Type: Abstract Only
Publication Acceptance Date: September 9, 2005
Publication Date: March 6, 2006
Citation: South, P., Smith, A.D., Guidry, C.A., Levander, O.A. 2006. Effect of physical restraint on oxidative stress in mice fed a selenium and vitamin e deficient diet[abstract]. Biological Trace Element Research. 109(3):293-300. Interpretive Summary: Previous work demonstrated that a benign form of coxsackievirus caused heart damage in infected mice that were on diets deficient in the micronutrients selenium (Se) or vitamin E (VE). Physical restraint (immobilization) as a form of stress has also been shown to induce oxidative tissue damage in animals, and has been considered as a surrogate for infection. The purpose of this study was to determine whether the oxidative damage caused by the stress of restraint could be increased in animals fed a nutritionally deficient diet. We found, however, no evidence of a synergistic effect between diet and stress under the conditions tested. This information will benefit mainly scientists interested in the interaction between nutrition and stress, and indicate that more complex protocols are needed to evaluate interactions that may be damaging to health.
Technical Abstract: Physical restraint has been associated with increased oxidative damage to lipid, protein and DNA. The purpose of this experiment was to determine whether physical restraint would further exacerbate oxidative stress in mice fed a Se and vitamin E deficient diet. Three week-old mice were fed a Torula yeast diet containing adequate or deficient Se and vitamin E. Menhaden oil was added to the deficient diet to impose an additional oxidative stress. After 4 weeks feeding, half the mice in each group were restrained for 5 days in well-ventilated conical tubes for 8 hours daily. Mice fed the Se and vitamin E deficient diets had increased liver thiobarbituric acid-reactive substance (TBARS) levels and decreased liver glutathione peroxidase (GPX1) and a-tocopherol levels. Plasma corticosterone levels were elevated in restrained mice fed the deficient diet compared to unrestrained mice fed the adequate diet. Restraint had no effect on liver TBARS or a-tocopherol levels. Liver GPX1, however, was lower in restrained mice fed the adequate diet. In addition, liver superoxide dismutase (SOD) was lower in the restrained mice fed the adequate or deficient diet. Thus, under our conditions, diet but not restraint increased lipid peroxidation in mice.